Migratory shorebird adheres to Bergmann’s Rule by responding to environmental conditions through the annual lifecycle

Authors

Daniel Gibson, Virginia Polytechnic Inst. and State Univ.Follow
Angela D. Hornsby, Virginia Polytechnic Inst. and State Univ & State Univ. of New York
Mary B. Brown, University of Nebraska–LincolnFollow
Jonathan B. Cohen, Nebraska Game and Parks Commission, Lincoln
Lauren R. Dinan, Nebraska Game and Parks Commission, Lincoln
James D. Fraser, Virginia Polytechnic Inst. and State Univ.
Meryl J. Friedrich, Virginia Polytechnic Inst. and State Univ.
Cheri L. Gratto-Trevor, Science and Technology, Environment and Climate Change Canada
Kelsi L. Hunt, Virginia Polytechnic Inst. and State Univ.
Matthew Jeffery, National Audubon Society, New York
Joel G. Jorgensen, Nebraska Game and Parks Commission, LincolnFollow
Peter W.C. Paton, Univ. of Rhode Island
Samantha G. Robinson, Virginia Polytechnic Inst. and State Univ.
Jen Rock, Canadian Wildlife Service
Michelle L. Stantial, Canadian Wildlife Service
Chelsea E. Weithman, Virginia Polytechnic Inst. and State Univ.
Daniel H. Catlin, Virginia Polytechnic Inst. and State Univ.

ORCID IDs

https://orcid.org/0000-0003-1580-1479

https://orcid.org/0000-0003-4637-0384https://orcid.org/0000-0003-0927-2101

Document Type

Article

Date of this Version

5-3-2019

Citation

2019 The Authors. Ecography

2019 Nordic Society Oikos

Comments

Ecography 42: 1482-1493, 2019 dio: 10.1111/ecog.04325

Abstract

The inverse relationship between body size and environmental temperature is a widespread ecogeographic pattern. However, the underlying forces that produce this pattern are unclear in many taxa. Expectations are particularly unclear for migratory species, as individuals may escape environmental extremes and reorient themselves along the environmental gradient. In addition, some aspects of body size are largely fixed while others are environmentally flexible and may vary seasonally. Here, we used a long-term dataset that tracked multiple populations of the migratory piping plover Charadrius melodus across their breeding and non-breeding ranges to investigate ecogeographic patterns of phenotypically flexible (body mass) and fixed (wing length) size traits in relation to latitude (Bergmann’s Rule), environmental temperature (heat conservation hypothesis), and migratory distance. We found that body mass was correlated with both latitude and temperature across the breeding and non-breeding ranges, which is consistent with predictions of Bergmann’s Rule and heat conservation. However, wing length was correlated with latitude and temperature only on the breeding range. This discrepancy resulted from low migratory connectivity across seasons and the tendency for individuals with longer wings to migrate farther than those with shorter wings. Ultimately, these results suggest that wing length may be driven more by conditions experienced during the breeding season or tradeoffs related to migration, whereas body mass is modified by environmental conditions experienced throughout the annual lifecycle.